1. Field
The following description relates to a power amplifier (PA). The following description also relates to a method of controlling an output of a power amplifier.
2. Description of Related Art
A power amplifier may amplify a low RF signal having a preset frequency, such as a center frequency, f0, to output a high RF signal. In general, when the power amplifier outputs a RF signal having a maximum level, efficiency of the power amplifier is significantly increased, and as power of an output RF signal is decreased, the efficiency of the power amplifier may be reduced.
As a way to increase the efficiency of a power amplifier at low power output and medium power output levels, a means of independently designing a power amplifier having high efficiency at low power output and medium power output levels and a power amplifier also having high efficiency at a high power output level, respectively, may be used.
However, since such an approach additionally requires a switch, a low power amplifier, and other appropriate components, there are potential problems in that a circuit and a corresponding structure may be relatively complex and accordingly a size of such an integrated circuit may be increased.